Plumbing apparatus

Abstract

A continuous, synthetic plastic plumbing trap comprising a generally U-shaped tubular structure having a first opening comprising an outer threaded annular rim, which is adapted to form a seal with an outer rim surface of a downstream tubular member, and an inner annular rim which is adapted to form a seal with an inner rim surface of a downstream tubular member, the inner and outer annular rims of the trap opening being so situated as to accommodate any tubular downstream member having a rim which fits between the inner surface of the threaded annular rim and the inner annular rim; and a second opening comprising a threaded annular rim, both said threaded annular rims being adapted to engage fastening means of the same size.

What is claimed is: 
     
       1. A tubular trap adapted to conduct liquids, interconnect an upstream, tubular, liquid-conducting member to a downstream, tubular, liquid-conducting member and retain a pool of trapped liquid when liquid is not being conducted therethrough: said trap comprising a tubular structure having an inside and an outside surface and a generally U-shaped bend;   a first opening at one end; and   a second opening at the other end;   said first opening comprising a threaded outer annular rim having an inner annular bearing surface adapted to intimately contact a mating surface of an inlet opening of a downstream liquid conducting member; and an inner annular rim having an outer bearing surface adapted to intimately contact a mating surface of an inlet opening of a downstream liquid-conducting member; said inner bearing surface of said outer annular rim and said outer bearing surface of said inner annular rim together forming a generally V-shaped cross-sectional configuration;   said inner and outer annular rims of said first opening of said trap being situated with respect to one another as to permit said first opening of said trap member to be fastened to an inlet opening of a downstream member which comprises an annular inlet rim element having a diameter between the largest diameter of said inner annular bearing surface of said outer annular rim and the smallest diameter of said outer annular bearing surface of said inner annular rim of said trap,   whereby intimate contact between the inner surface of the outer annular rim of the trap with a mating surface of the inlet opening of a downstream liquid-conducting member, and intimate contact between the outer surface of the inner annular rim of the trap with a mating surface of the inlet opening of a downstream liquid-conducting member provides a double seal against leakage when said first opening of said trap is fastened to the inlet opening of a downstream member;   said second opening of said trap comprising a threaded annular rim having a diameter equal to the diameter of the threaded annular rim of said first opening so that both threaded annular rims are adapted to be engaged by fastening means of the same size.   
     
     
       2. The trap of claim 1 wherein the vertical dimension from the lowermost portion of said generally U-shaped bend to said first opening of said trap is less than the vertical dimension from the lowermost portion of said generally U-shaped bend to said second opening, thereby producing a generally J-shaped trap configuration. 
     
     
       3. The trap of claim 1 wherein the U-shaped bend comprises a constant outside diameter and a continuously increasing inside diameter from the portion of said bend closest to the second opening of said trap to the portion of said bend closest to the first opening of said trap. 
     
     
       4. The trap of claim 3 wherein the surface of the inner annular rim comprising said first opening is coincident with the inside surface of said trap and continuously flares to a diameter greater than the largest inside diameter in the U-shaped bend of the trap.